That patch hasn't been included in official builds because there's never been any hard evidence it actually improves sound quality. saratoga's most recent post on that is here http://www.anythingbutipod.com/forum...&postcount=508 IIRC, dfkt said in other places he never heard an improvement. It was just something he threw in for testing.

I've tested builds with that patch included on several targets with multiple headphones and the only difference I found was I lost a bit of battery life. As there was no audible improvement for me I didn't see a reason to use the custom build that included it and moved on.